Lyme Disease in Travelers: A Missed Diagnosis Abroad
Lyme disease in travelers is often missed when clinicians in non-endemic regions fail to consider exposure history.
This case highlights how easily Lyme disease can be overlooked when symptoms present outside of North America or Europe.
A Misleading Presentation in Japan
A woman living in New York for 10 years returned to Japan to visit family. She developed difficulty opening her mouth and facial asymmetry.
Initially, a neurologist suspected tetanus, a more common diagnosis in the region.
However, closer examination revealed facial paralysis:
- Unilateral mouth drooping
- Inability to close one eye
- Limited jaw opening
This shift in diagnosis changed the clinical trajectory.
The Missing Clue: Travel History
Further questioning revealed a critical detail:
The patient had been bitten by a tick while camping in Pennsylvania 3 months earlier.
She also reported a rash consistent with erythema migrans and a low-grade fever shortly after exposure.
Despite these clues, Lyme disease was not initially considered.
Why Lyme Disease Is Missed Outside Endemic Regions
In countries like Japan, Lyme disease is not commonly included in the differential diagnosis of fever of unknown origin (FUO).
Instead, clinicians often focus on:
- Local infectious diseases
- Autoimmune conditions
- Malignancy
This geographic bias can delay diagnosis and treatment.
Diagnosis and Recovery
The patient ultimately tested positive for Lyme disease.
After 2 weeks of oral minocycline, her symptoms resolved, including:
- Facial weakness
- Fatigue
- Difficulty closing her eye
This case underscores how treatable Lyme disease can be when recognized.
Clinical Takeaway
Clinicians evaluating patients with neurologic symptoms or fever of unknown origin should always ask about travel history and prior tick exposure.
Lyme disease does not respect geographic boundaries. Missing the diagnosis can lead to unnecessary testing, delayed treatment, and prolonged symptoms—especially in returning travelers.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
I couldn’t agree more with the headline, clinicians in foreign countries should consider Lyme disease with symptomatic travelers! This should be louder! These infectious diseases shouldn’t be carried around by any person especially those who are travelling one country to another.